Switch-interlocking mechanism



Patented pr. 20, 1926A'. i

'DAVID C. LABSON, 0F YONXEBS, NEW YORK, ASSIGNOR T0 OTIS ELEVATOR CQEPAN'Y, OF JERSEY CITY, NEW JERSEY, CRPORATION 0F NEW JERSEY.

SWITCH-INTBLOCKING MECHNISM.

To all whom it 'may concern.'

Be it known that I, DAVID C. LAnsoN, a citizen of the United States, residing in Yonkers, in the county of Westchester and State of New York, have invented a new anduseful Improvement in Switch-Interlocking Mechanism, ot which the following is a specification. A

My invention relates to mterlockin means for switches and particularly to mec anical interlocks for magnet switches.

One object of m invention is to provide' `a mechanical inter ock between two magnet switches whereby the simultaneous closing of two switches is prevented, and the closing of one switch prevents the closing of the second until the iirst switch has returned to its 4open position.

` Another object of my invention is to pro. vide a mechanical interlock between two orl more magnet switches whereby the sequence of the closing and opening of these switches is definitely fixed, and more specifically, the

opening sequence is required to be in the re` verse order of the closing sequence.

Other objects will appear from the specitication and claims. j

My invention will be described by way of example in connection with two switchesA as shown-in the accompanying drawings in which:

Fi 1 is a Vplan view oi two magnet switc es in open position and illustrates an embodiment of m interlock forA preventing the closing of eit er switch when the other is closed.` Y

Figure 2 is an enlarged fragmental plan l vview. of the interlock of Figure 1 with one switch'in the closed position.

Fi e 3' is a plan view of two magnet switch; in`open-position and illustrates my interlock for establishing the sequence of closing and opening ofthe two switches.

Figure 4 is an enlarged fragmental plan view 'ofthe interlock of Fi 3 with both switches in the closed ositlon.

Fi e 5 is an Ve evation of 'the two switc es and interlock shown in Figure 1 with;v one switch closed and the other open.

Like numerals refer to like parts throughout the several views.

, Referringto Figures l 2 and 5 magnet switches A andB are mdunted on tromagnetically by energization of suitable coils and to be opened by the action of avity upon de-energization of the coils.

witch A comprises magnet coil 2 and movable core 3 which is connected to switch arm 4 by rod 5 through pivot 35. Stationary contacts 6 and 7 are mounted on panel 1 and movable contacts 8 and 9 are mounted on switch arm 4. Lug 10 is provided on switch arm 4to engage the interlock device. Similarly switch B is provided with a coil, core, and contacts, thestationary contacts 11 and 12 being mounted on panel 1 and the movtiti able contacts y13 and 14 being mounted on vided with a `V-shaped end having surfaces 25 and 26.

Assuming switches A and B open as shown in Figure 1, the energization of the coil 2 of switch A causes core -3 to be Vdrawn within the coil 2, so that switch arm 4 moves around hinge pin 27 in switch arm support 28 to close contacts 6 alud 8, and 7` and 9. Switch arm support 28 is secured to xpanel 1 by bolts 29. As the switch arm 4 moves, lug 10 on thisarm strikes against surface 25 of cam 23, 'thereby-pushing the cam 23 to one side around pin 20 as 'a center. Cam 23 and the lugs 10 and 16 on switch arms 4 and 15 respectively are .so positioned that lng 10 may pass entirely oi the surface 25 of cam 23v before surface 26 of the cam strikes vagainst lug 16 on arm 15 of switch B. It

will be noted that :with switch A closed,

switch B is mechanically locked in the o position. This is due-to the action of ug 10 in holding cam 23vv stationary a movement by pressure of lug 16 on t e inclined surface 26. When swlteh B is closed and switch A is open,the conditions arereversed vfrom that shown in Flgure 2, switch lA being :locked in the open position as long as switch B is closed. The motion of cam 23,-rod 21 and yoke 19 i s by either projection 28 or 29 on' yoke -19 striking against either projection 30 or 31 on sup port 17, the object being to keep kcam 23 from swinging about pivot beyond a point atwhich it can be engaged by lugs 10 or 16; v

The parts shown in Figures 3 and 4 are the same as those shown in Figures l and :2 with the exception ofi the. interlock cam. which has means for preventing closing of the switches in any but a. predetermined sequence, and means for preventing the openof the switches in any but the reverse or er of their closing. The cam shown in Figures 3 and 4 is interposed in the path of movement of switch B and is provided with an oblique surface 33 and slot 34. In

this case switch Amnst be closed before switch B, as when both switches are open, Ing 10 on arm 4 of switch A is interposed in ther` path of deflection of cam 32 and thus prevents it from moving to permit switch B to close. After switch A has closed, switch B can then close, the Ing 16 on arm 15 of switch B striking againstsnrface 33 of cam 32, thereby pushing the cam toward switch A so thatlng 10 enters slot 34. lVhen both switches are closed switch B must open first, as lug 10 on arm 4 is held in slot. 34-as long as Ing 16 is against the side of cam Switch A is thus prevented from opening until after switch B has opened. It fili be noted that with the interlock shown in Fig- -nres 3 and 4, ladefinite sequence of operation 0f the switchesris assured both in opening and closing, i. et, the one that eioses first must open last. Although I have shown but two switches in the drawing, it will be understood that my interiock may be ap-A piied to any the sequence of operationi `tioned switch arm.

umher of switches to cont-rol' I claim:

1. Interlock mechanism for electromag netic switches comprising in combination a pair of switch arms, and a locking cam' interposed in the operating path of one of said arms but movable thereby into the operating path of the other arm to lock said other arm in position. i

2. Interlock mechanism for. electromagnetic switches comprising in combination a switch arm, a. locking cam interposed in the operating path of said arm but deflectnble thereby to permit said arm to operate, and a second switch arm normally interposed in the path of deection of said lockingcam but removed therefrom when operated.

3. Interlock mechanism for electromagnetic switches comprising in combination :1-

'but removed therefrom when operated, said lockingl cam having means to hold saidnorlnally interposed armkin its shiftedposition f while said cam is deflected by the first men- In testimony whereof, I have signed .my

name to this specification. f DAVID C. LARSON. 

